Low-water alarm



2 Sheets-Sheet 1. W. R. FOX.

(No Model.)

Patented Sept. 2, 1890.

M. nn... L M M E M W (No Model.) 2 Sheets-Sheet 2.

W. R. FOX.

Low WATER ALARM.

No. 435,742. Patented Sept. 2, 1890.

j I Vw t A .f

o I j l\ UNITED STATES PATENT OEEICE.

WILLIAM R. FOX, OF GRAND RAPIDS, MICHIGAN.

LOW-WATER ALARM.

SPECIFICATION forming part of Letters Patent No. 435,742, datedSeptember 2, 1890.

Application filed February l1, 1890. Serial No. 340,026. (No model.)

To @ZZ whom it may concern:

Be it known that I, WILLIAM R. FOX, of Grand Rapids, in the county ofKent and State of Michigamhave invented a new and useful Improvement inLow-lVater Alarms; and I do hereby declare that the following is a full,clear, and exact description of the same.

The invention which is the subject of the -foregoing petition relates toautomatic high and low water alarms of that class in which the alarm iscaused by the expansion of a tube into which the steam is admitted bythe fall of the water in the boiler below a certain line. Such alow-water alarm is shown in Letters Patent of the United States grantedto Hardwick on the 24th day of December, A. D. 1889, and numbered418,020. The alarm described in the said patent is operative asexplained therein; but my said invention is designed to secure certainadvantages not secured by the construction in the said patent and not tothe best attainable extent. I retain the tube extending down into theboiler to the line of low water; but in the patent the expansion of thetube acts directly upon a bell-crank lever, which moves a sliding valveto open the passage for the steam to the Whistle. In this construction aconsiderable amount of force is required, as the valve is under pressureof steam, which must be overcome by the pressure arising from theexpansion of the tube. Further, in the patented alarm some trouble isexperienced in securing the right adjustment between the lever whichconnects the expansible tube with the valve, so that when the watershould fall below the end of the pipe and the steam be admitted thereinthe whistle should sound suficiently to be heard, while avoiding sosensitive an adjustment that the whistle would not be sounded when fromany cause other than the admission of steam the tube should becomehotter than usual. In respect to this point, my invention, in which thevalve is directly operated by an intermediate motorsuch as a weight, andnot directly-the expansible tube requires much less expansion andrenders the alarm operative with a full opening of the whistle-valve atthe lowest steam-pressure, the lowest ordinary pressure givingsuiiicient expansion to release the weight.

Another detect in the patented alarmIhave sought to remedy-namely thatby reason of the slow cooling of the pipe the whistle would continue tosound from ifteen to forty-five minutes after the water in the boilerhad been restored to its high level, and this could not be convenientlyprevented.

Further, my invention is designed, by reason of a straightexpansion-pipe and removable cap operated by the expansion, to allow thepipe to be readily cleaned, as that above referred to cannot be.

My said invention therefore consists, essentially, in combining with anexpansible tube and a whistle-valve an intermediate motorsuch as aweight-arranged to act on said valve or the force of the steam-pressure,and a lever operated by the said expansible tube, arranged to set theintermediate motor in operation.

My invention also includes the special details ot' construction which Ihave found best in carrying my invention into effect.

In the accompanying drawings, which illustrate my invention, Figure lrepresents the alarm with a weight as the intermediate motor held out ofoperation, the ligure being in side elevation, but showing part of theboiler in section. Figs. 2 and 3 show modifications.

In the drawings, Arepresents apart of the boiler. In the top is screweda casting B, which is formed with one straight stem b and alaterally-bent stem c. The straight stem is tubular and opens directlythrough the casting. The upper end receives t-he expansible tube D, andin the lower end is fixed the tube d, which forms a straightcontinuation of the expansible tube and extends to the low-water limit.The lateral stem c receives the tube E, which supports the whistle F andconducts steam thereto, the iiow of steam being controlled by a valveheld normally closed by a spring on the stem f of the valve. Theexpansible tube D is made preferably of copper, and may be convenientlyused about twenty-four inches iu length. The lower end communicates withthe interior of the boiler on the line mentioned, and

IOC

the upper end is closed by the movable plug. This upper end is heldloosely in the end of an arm G, fixed upon the steam-tube E, so that thecopper pipe in expanding may move freely in the arm. The said arm has averti` cal slot, in which is pivoted at 1 a bell-crank lever M, theupper short arm'of which carries an adj Listing-screw and extends overthe upper end of the expansible tube, the screw bearing on said end. Thelower arm of said lever is longer and projects into range with a leverN, pivoted on the steam-pipe E. The lever is formed on a ring encirclingthe pipe E and has pivoting trunnions 3. The inner extension 0 of thislever has a notch 4, iitted to receive the edge of the lower end of thebell-crank lever, and when the levers are in Contact the outer end p ofthe lever N is held upV and sustains a weight. This weight is connectedto the lever Q by a cord or chain q, the said lever being pivoted on thebracket above the valve-stem. The lever Q has a stud which bears on theend of said stem, and when the lever is pressed down, as by the weightP, it presses on the stem and operates the valve, giving full passage ofthe steam to the whistle. The weight is hung upon the end p of the leverN, and in this position is held by the bell-crank lever, as aforesaid.When the water falls in the boiler, thereby the steam is admitted to thepipe, ex-

panding it and raising the upper arm of the bell-crank lever. A veryslight movement and force are required for this, and thereby the lowerarm of the lever is removed from the leverN, permittingwthe weight tedropYi from the other end p, wit-h the result stated above. The partsare so arranged that the inner end of the lever N falls by gravity afterthe release of the weight, and the long arm of the bell-crank leverswings down by gravity over said inner end, and to restore the parts tonormal position it is only necessary to hang the weight again on the armp. As the valve is operated solely by the intermediate motor, theexpansible tube has no work to perform, excepting that it releases themotor, which requires but very slight movement. The relation of thebell-crank lever to the tube D may therefore be easily adjusted and withperfect accuracy to secure release only when the tube is filled with thesteam, and the weight or other intermediate motor may be made of anyrequired power sufficient to move the valve under any circumstances. v

To restore the valve and stop the whistle,

or other intermediate motor off from the lever which operates the stemof the valve, or to push the valve to its seat and secure it. This maybe done by means of a cord t, attached to the weight and passing over apulley u down to convenient position within reach of the attendant. Theweight may at any time be restored to its place as soon as the tube D iscooled. The expansible tube is liable to it isnecessary only to taketheforce of weight Y become clogged by scum formed from the surface ofthe water in the boiler, and thus the alarm rendered inoperative. Toremedy this in my improved construction, it is necessary only to removethe bell-crank lever by taking out the removable gib on which it ispivoted and remove the plug from the top of the tube. Then a swab maybeinserted, and as the tube D is straight this swab may be pushed throughto the lower end of the tube.

While I have shown the weight as the simplest and a perfectly effectiveform of intermediate motor, it will be readily understood that a springmay be substituted therefor, and this spring may operate to open thevalve, while the valve is held normally closed by the intermediatelever, or the pressure of the steam may be utilized as an intermediatemotor.

In Fig. 2 I have shown a form in which the steam acts as theintermediate motor. The valve at Vis a puppet-valve, and is seated onthe perforated diaphragm and opens by steam-pressure. Its stemfu bearson the lever P', which is held with the valve sealed by means of theupturned end of the lever N, and when the lever N is released, as abovedescribed, the valve opens by the force of the steam acting as theintermediate moto-r, with the effect explained. l

To cause the bell-crank lever to engage with the inner end of the leverN, it may have a l weight K and to secure the movement of the `lever N,I add a cord, by which it may be pulled down to engage with the otherlever. I add also in Ythis modification an arm 7 to the lever 1) with acord 9, by means of which the valve may be closed before the expansibletube has cooled suficiently to reset the alarm.

The position of the parts when properly set is shown in full lines, thedotted lines represening the position when the device is oper` ate InFig. 3 I have shown a modification, in which I have added to the deviceheretofore described a high-water alarm. An expansible tube B extendsloosely through the bracket and down into the boiler to the highwaterline. It has an arm b extending over an opposite arm 5 of the bell-cranklever provided with an adjustingscrew, which bears on the arm. When thehigh-water rises in the tube B', it cools and contracts it, drawing downthe opposite extension 5, releasing also the valve-operating mechanism.

The lever is pivoted at :c to an ear on a sleeve which is held on thepipe by means of ascrew. The lever M has a bend, by means of which itits around the sleeve loosely enough to allow it to turn on its pivotand drop when the lever M is forced out by the expansion, as aforesaid,and when the lever drops it ceases to act as a stop, as beforeexplained.

I claim as my invention-un l. In combination with an expansible tubeextending into the boiler and with a pipe IOO IIO

having a Whistle and Whistle-valve, a lever operated by the expansion ofthe tube, and an intermediate motor arranged to be set in action by thelever to operate the Whistlevalve, substantially as described.

2. A high-Water alarm consisting of the tube of expansible materialextendingthrough the boiler to the high-Water line and held therein withits upper end loosely held in the bracket, a lever arranged to be drawndown by the said tube, and an intermediate motor normally in engagementwith said lever and being also arranged to operate the Whistlevalve,Substantially as described.

3. In combination with the Whistle and valve, an expansible tube D, ahigh-Water tube B', a pivoted lever arranged to be operated by theexpansion of the tube D and the Contract-ion of the tube B', and a motorarranged to be set in action by the lever to operate the whistle,substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

XVILLIAM R. FOX.

Vitnesses: l

THEO. H. MCCALLA, E. HOWARD BURKE.

